Combined simulated annealing and Shinnar-Le Roux pulse design of slice-multiplexed RF pulses for multi-slice imaging.
J Magn Reson
; 182(1): 133-42, 2006 Sep.
Article
in En
| MEDLINE
| ID: mdl-16828567
ABSTRACT
Slice-multiplexed RF pulses have recently been introduced for simultaneous multi-slice imaging. Their novel aspect is that each slice is given a different linear phase profile, and hence a different slice-rephasing requirement, by the pulse. During readout, extra slice gradients are applied such that when one slice is rephased, the others are dephased to prevent aliasing. In this paper, an improved method of designing slice-multiplexed RF pulses is presented component pulses which are optimized with simulated annealing for a specific rephasing are combined using Shinnar-Le Roux methods. In this way, non-linearities at higher flip angles are taken into account and more slices can be excited. Bloch simulations show the phase and amplitude profile of component pulses are faithfully preserved in the multiplexed pulse. Three- and four-slice multiplex pulses are demonstrated in gradient- and spin-echo in-vivo imaging.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Brain Mapping
/
Magnetic Resonance Imaging
Limits:
Humans
Language:
En
Journal:
J Magn Reson
Journal subject:
DIAGNOSTICO POR IMAGEM
Year:
2006
Document type:
Article
Affiliation country:
United kingdom